diff --git a/nicegui/element.py b/nicegui/element.py
index c03478cc8..33a58a060 100644
--- a/nicegui/element.py
+++ b/nicegui/element.py
@@ -39,9 +39,10 @@ def __init__(self, tag: str, *, _client: Optional[Client] = None) -> None:
         if slot_stack:
             self.parent_slot = slot_stack[-1]
             self.parent_slot.children.append(self)
-            outbox.enqueue_update(self.parent_slot.parent)
 
         outbox.enqueue_update(self)
+        if self.parent_slot:
+            outbox.enqueue_update(self.parent_slot.parent)
 
     def add_slot(self, name: str) -> Slot:
         self.slots[name] = Slot(self, name)
diff --git a/nicegui/outbox.py b/nicegui/outbox.py
index 2dcbb9c2a..89ed13f27 100644
--- a/nicegui/outbox.py
+++ b/nicegui/outbox.py
@@ -1,56 +1,41 @@
 import asyncio
-from collections import deque
-from typing import TYPE_CHECKING, Any, Deque, Dict, Set, Tuple
+from collections import defaultdict, deque
+from typing import TYPE_CHECKING, Any, DefaultDict, Deque, Dict, Tuple
 
 from . import globals
 
 if TYPE_CHECKING:
     from .element import Element
-    ClientId = int
-    MessageType = str
-    MessageGroup = Tuple[ClientId, MessageType, Any]
-
-queue: Deque['MessageGroup'] = deque()
-
-
-def enqueue_update(element: 'Element', *attributes: str) -> None:
-    client_id, message_type, data = queue[-1] if queue else (None, None, None)
-    if client_id != element.client.id or message_type != 'update':
-        # add new message group
-        queue.append((element.client.id, 'update', {element.id: (element, set())}))
-        return
-    elements: Dict[int, Tuple[Element, Set]] = data
-    if element.id not in elements:
-        # add new element to message group
-        elements[element.id] = [element, set()]
-        return
-    if attributes:
-        # enqueue single attributes
-        elements[element.id][1].update(attributes)
-    else:
-        # enqueue all attributes
-        elements[element.id][1].clear()
+
+ClientId = int
+ElementId = int
+MessageType = str
+Message = Tuple[ClientId, MessageType, Any]
+
+update_queue: DefaultDict[ClientId, Dict[ElementId, 'Element']] = defaultdict(dict)
+message_queue: Deque[Message] = deque()
+
+
+def enqueue_update(element: 'Element') -> None:
+    update_queue[element.client.id][element.id] = element
 
 
 def enqueue_message(message_type: 'MessageType', data: Any, client_id: 'ClientId') -> None:
-    _convert_elements_to_dicts()
-    queue.append((client_id, message_type, data))
+    message_queue.append((client_id, message_type, data))
 
 
 async def loop() -> None:
     while True:
-        while queue:
-            _convert_elements_to_dicts()
-            client_id, message_type, data = queue.popleft()
-            await globals.sio.emit(message_type, data, room=client_id)
-        await asyncio.sleep(0.01)
-
-
-def _convert_elements_to_dicts() -> None:
-    _, message_type, data = queue[-1] if queue else (None, None, None)
-    if message_type == 'update':
-        elements: Dict[int, Tuple[Element, Set]] = data
-        for id, value in elements.items():
-            if len(value) == 2:
-                element, attributes = value
-                elements[id] = element.to_dict(*attributes)
+        if not update_queue and not message_queue:
+            await asyncio.sleep(0.01)
+            continue
+        coros = []
+        for client_id, elements in update_queue.items():
+            elements = {element_id: element.to_dict() for element_id, element in elements.items()}
+            coros.append(globals.sio.emit('update', elements, room=client_id))
+        update_queue.clear()
+        for client_id, message_type, data in message_queue:
+            coros.append(globals.sio.emit(message_type, data, room=client_id))
+        message_queue.clear()
+        for coro in coros:
+            await coro